Intel ETHEREXPRESS PRO/100, Руководство по установке

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ing) allows the adapter to work with other elements of the network (switches,
routers) to deliver priority packets first. 802.1p tagging enables you to assign
specific priority levels from 0 (low) to 7 (high).
Using the IEEE 802.1p standard for packet tagging, you can assign values to
packets based on their priority. This method requires a network infrastructure
that supports packet tagging. The routing devices receiving and transferring
these packets on your network must support 802.1p for tagging to be effective.
After you set up the priority filter in Priority Packet, you must launch Intel
PROSet and select 802.1p/802.1Q Tagging on the Advanced tab.
CAUTION: IEEE 802.1p tagging increases the size of the packets it tags. Some
hubs and switches won’t recognize the larger packets and will drop
them. Check your hub or switch documentation to see if it supports
802.1p. (You can configure the switch to strip the tags from the pack-
ets and send it on to the next destination as normal traffic.) If these
devices don’t support 802.1p or you’re not sure, use High Priority
Queue (HPQ) to prioritize network traffic.
The requirements for effectively using IEEE 802.1p tagging are:
•
The other devices receiving and routing 802.1p tagged packets must
support 802.1p.
•
The adapters on these devices must support 802.1p (adapters using the Intel
82558 or later Ethernet controller). All PRO/100+ and PRO/100 S Manage-
ment Adapters support 802.1p. PRO/100B Client Adapters (using the
82557 Ethernet controller) do not.
•
The adapter(s) cannot be assigned to an adapter team.
•
If you’re setting up VLANs and packet tagging on the same adapter, you
must select the 802.1p/802.1Q Tagging and the Enable option on the Intel
PROSet Advanced tab.
Intel High Priority Queue
If your network infrastructure devices don’t support IEEE 802.1p or you’re not
sure, you can still define priority filters and send packets as high priority. While
High Priority Queue (HPQ) doesn’t provide the precise priority levels of 802.1p
tagging, it does assign traffic as either high or low priority, and sends high prior-
ity packets first. Therefore, if there are multiple applications on a system send-
ing packets, the packets from the application with a priority filter are sent out
first. HPQ doesn't change network routing, or add any information to the
packets.
To assign HPQ, you can specify it using Priority Packet when you create or
assign a priority filter.
To effectively use HPQ tagging, the adapter(s) cannot be assigned to an adapter
team.